1. Field of Invention
This invention relates to a reinforced stabilising strip intended for use in reinforced earth or strengthened soil structures, together with the use of such a strip for the construction of reinforced earth or strengthened soil structures.
2. Description of the Prior Art
A reinforced earth structure combines compacted backfill, a facing and reinforcements that are connected or not to the facing.
Various types of reinforcement can be used: metal, for example galvanised steel, or stabilising strips, for example polyester fibre-based. They are placed in the earth at a density that depends on the stresses that are likely to be exerted on the structure, with the thrust stress of the ground being taken up by the friction between the earth and the reinforcements.
The facing is usually made from precast concrete elements in the form of slabs or blocks, juxtaposed to cover the front surface of the structure.
In the great majority of cases, the reinforcements are provided in the form of strips approximately 3 to 10 metres in length, although shorter or longer strips can be used.
The width of the strips is generally between 4 and 6 centimetres, although it is possible to use strips ranging from 10 to 25 centimetres in width, or even more. Their thickness varies, for example, between approximately 1 millimetre and a few centimetres, and is generally between 1 and 6 millimetres.
Non-reinforced strips or strips reinforced by means of metal rods or parallel fibres or strands of yarn exist.
The aim of the stabilising strips is to transmit the forces into the soil or the earth and thus distribute the stresses.
In particular, it is necessary to transmit the forces between a strip and the backfill in which it is placed. The strip must therefore have a sufficient surface area to develop, through friction, the required shear strength per unit of length.
Moreover, the strip is preferably capable of transmitting the stresses along its entire length, and therefore has high tensile strength.
One solution known to a person skilled in the art consists of using strips comprising a longitudinal part in the form of a central part to withstand a tensile force, the central part having two lateral parts that protrude laterally on either side of the central part to rub against the earth, the central part comprising a set of fibres arranged parallel to each other in such a way as to increase the tensile strength.
Another solution consists of using parallelipedal polyethylene strips reinforced with polyester fibres arranged parallel to each other in the bulk of said strip.
In the prior art, the internal reinforcements of the strips are made up of approximately parallel bundles of strands of yarn approximately parallel to each other. Such an arrangement of the fibres poses the risk of sliding between fibres and between a group of fibres and the strip, and thus a reduction in the transmission of the stress between the earth and the part of the strip with tensile strength.
One object of this invention is to propose another solution that allows for the forces to be transmitted between a strip and the backfill in which it is placed, that has high tensile strength and that limits the risk of sliding between fibres and between a group of fibres and the strip.
The invention thus proposes a reinforced stabilising strip intended for use in reinforced earth structures, comprising a longitudinal part, said longitudinal part comprising along at least a part of its length, at least one cord arranged approximately longitudinally and embedded in the bulk of said longitudinal.